People gather at a memorial service held at Poway High School for teenager Chelsea King Saturday March 13, 2010, in Poway, Calif. Thousands of people attended the memorial for the 17-year-old girl whose murder has shaken her community and spurred ...
— / AP

Members of the Poway High School soccer team arrive at a memorial service held at Poway High School for teenager Chelsea King Saturday March 13, 2010, in Poway, Calif. Thousands of people attended the memorial for the 17-year-old girl whose ...
— / AP

Brent King, father of Chelsea King, bent his arms in a certain way just like Chelsea used to, to loosen up before he spoke to people gathered for the memorial.
— John Gastaldo / San Diego Union-Tribune

Poway High School was the site of Saturday's Chelsea King Memorial on the Football Field//Track at Poway High School. Many in the audience held hands and wore Chelsea's favorite color orange.
— John Gastaldo / San Diego Union-Tribune

Carrie McGonigle hugged San Diego County Sheriff's Sgt. Don Parker on the field before the start of the service. McGonigle, mother of Amber Dubois was there with Amber's father Moe Dubois.
— John Gastaldo / San Diego Union-Tribune

Derek Van Dam, brother of Danielle Van Dam was dressed in black as he joined the Poway High School band playing alto sax. Derek lost his sister eight years ago to David Westerfield who was convicted in her murder.
— John Gastaldo / San Diego Union-Tribune

An afternoon of fond and funny testimonials about Chelsea King ended Saturday with her father issuing a sharp call for action.

It’s incomprehensible that convicted sex offenders are allowed to live among families, Brent King said. And to those who disagree, he said, “Let them live in your neighborhood next to your children. Not ours.”

King urged the thousands gathered at Poway High School’s football stadium to embrace one of his daughter’s favorite words — give — and join the mounting effort to change the way society deals with sexual predators like the man accused of killing her.

Give your time, he said — even if it’s just one hour a month.

Give your voice, he said — even if it’s just to e-mail a legislator or cast a ballot.

And, he said, give your energy.

“This is about protecting our children from evil,” King said. “Pure evil.”

He did not name John Albert Gardner III, the convicted sex offender who took a plea agreement and was released in 2005 after five years in prison and who now stands accused of raping and killing Chelsea.

But when he said, “Known sexual predators are not curable,” it was one of the few statements in the service that was met with applause in midspeech.

Several people said after the memorial service they were moved by King’s words.

“It’s already happening with petitions that are going around school about predators,” said Austin Farrell, 16, a sophomore at Poway High School. “We have to do a better job tracking them.”

Carmen Morales, who attended with her family, including son Rodrigo, 16, also a sophomore, said, “The father is right. We should do more. They should never have let that guy out.”

Rodrigo said he wants to do “whatever I can to help.”

King, the last of more than a dozen speakers on Saturday’s program, said it would have been easy to wallow in despair after Chelsea went missing while heading out for a run on the dirt trails bordering Lake Hodges at Rancho Bernardo Community Park on Feb. 25. Her body was found five days later in a shallow grave at the water’s edge.

Chelsea could have run at a different park, he said. She could have picked a different trail, or a different time. But that wouldn’t have changed what happened, he said — just the victim. And he said he wouldn’t wish the loss and pain he is feeling on anybody.

Still, King’s call for change joins a rising chorus. Since Chelsea’s death, politicians and the public have been clamoring for tighter restrictions on sex offenders. Assemblyman Nathan Fletcher, a Republican who represents the district where the Kings live, is working with law enforcement on an unspecified “Chelsea’s Law.”

Almost 8,000 people have joined a “Support One Strike Law for Sex Offenders” group on Facebook.

King said it would have been easy to succumb to rage. He admitted he’s angry — hot enough, he said, to survive many days in hell — but he knows that’s not productive in the long run.

“Because of you,” he said, looking out at the audience, “I chose hope.”